Hermione's Twin

Yes, Hermione has a twin although she attended Beauxbatons until her fourth year. Harmonie is Hermione's identical twin sister, well almost identical, Harmonie has beautiful blue eyes instead of hazel. Harmonie is also very different from Hermione personality wise, she doesn't let anyone talk down to her, her family, or her friends, she also enjoys causing trouble such as pranks and flirting with boys that annoy her as a was of annoying them back. So what happens when they are suddenly stuck in the same school? Are both girls going to keep their heads around each other or will they lose it? You can only spend so much time with someone, even if they are you VERY best friend, right?